The present invention relates to a gaseous fuel discharging structure for use with a gaseous fuel containing tank disposed within a trunk of a vehicle, and in particular to the structure which, if gaseous fuel unfortunately leaks from within the tank, directs such gaseous fuel out of the trunk.
Gaseous fuel discharging structures for vehicles are well known in the art. One example of such structures is known from Japanese Patent Laid-Open Publication No. HEI-8-99544 entitled xe2x80x9cSTRUCTURE FOR AUTOMOBILE HAVING MOUNTED THERETO END OF PIPE FOR DISCHARGING LEAKAGE COMPRESSED GASEOUS FUELxe2x80x9d. The publication discloses an automobile having gaseous fuel containing tanks mounted within a trunk thereof. The tanks are connected to plural exits of a gas supply pipe. The gas supply pipes have one entrance provided in fluid communication with a filler formed in a recess positioned at a rear side wall portion of an automobile body.
The recess is covered with a cover. With the cover opened, the tanks can be filled with gaseous fuel supplied from the gas supply pipe.
The recess also has formed therein an opening which is in fluid communication with one discharge port of a gas discharge pipe. The gas discharge pipe has plural intake ports each connected to a junction at which each exit of the gas supply pipe is connected to the tank. Even if gaseous fuel undesirably leaks from within the tanks, such leaked gas flows into the intake ports of the gas discharge pipe out of the discharge port.
Since the recess is formed at the rear wall portion of the automobile body, the former is small in size to provide pleasant appearance of the automobile. This requires the gas supply pipe to have a limited diameter.
For the gas discharging structure disclosed in the publication, gaseous fuel leaked from within the tanks spontaneously flows through the gas discharge pipe out of the automobile body. In other words, such leaked gaseous fuel is slowly discharged into the open air. What has been needed is a structure for advantageously discharging the gaseous fuel into the open air.
Fuel-cell-powered automobiles typically employ hydrogen gas as gaseous fuel. For resinous tanks holding such hydrogen gas therein, the hydrogen gas could undesirably pass through the tank.
Especially for the fuel-cell-powered automobiles, therefore, there is required a structure for advantageously discharging into the open air the hydrogen gas leaked the tanks.
An object of the present invention is to provide a gaseous fuel discharging structure for a vehicle, which rapidly discharges gaseous fuel, leaked from within a fuel tank, into the air.
According to an aspect of the present invention, there is provided a gaseous fuel discharging structure for a vehicle having a trunk and a gaseous fuel containing tank disposed in a hermetic space defined within the trunk, which gaseous fuel discharging structure comprises: an air introducing pipe communicating with the hermetic space and extending to outside of the vehicle; a gas discharging pipe communicating with the hermetic space and extending to the outside of the vehicle; forced ventilation means disposed on at least one of the air introducing pipe and the gas discharging pipe for forcedly ventilating the hermetic space; and an opening/closing device disposed on each of the air introducing pipe and the gas discharging pipe, the opening/closing devices being held at a closed position to seal the air introducing pipe and the gas discharging pipe when the forced ventilation means is out of operation and, when the forced ventilation means is in operation, pivoted to an opened position so that any gaseous fuel leaked from the gaseous fuel containing tank into the hermetic space is forced out of the vehicle through the gas discharging pipe by fresh air flowing through the air introducing pipe into the hermetic space.
At least one of the air introducing pipe and the gas discharging pipe has a forced ventilating device. Each of the air introducing pipe and the gas discharging pipe includes the opening/closing device. Operation of the forced ventilating device causes the opening/closing device of the air introducing pipe to be opened so that air outside the vehicle is drawn through the air introducing pipe into the cover. Such air is discharged out of the gas discharging pipe along with the gaseous fuel leaked from the tank.
By thus driving the forced ventilating device in such a manner that the air outside the vehicle is forcibly taken into the cover, the gaseous fuel which remains within the cover after leaked from within the tank is rapidly discharged out of the vehicle along with the air. Accordingly, it becomes possible to efficiently ventilate a space formed within the cover.
As the forced ventilating device is out of operation, the opening/closing devices are held in the closed positions. Since these opening/closing devices normally close the air introducing pipe and the gas discharging pipe, noise is no longer transmitted through these pipes into a passenger compartment of the vehicle. Moreover, unwanted foreign materials such as water and dust are prevented from entering into the air introducing pipe and the gas discharging pipe.
In a preferred form of the present invention, the hermetic space is defined by a sealing cover hermetically enclosing the gaseous fuel containing tank, and the air introducing pipe and the gas discharging pipe extend outwardly of the vehicle from the sealing cover. The forced ventilation means may comprise a fan to be actuated upon leakage of the gaseous fuel. The opening/closing devices may comprise flaps to be pivoted to the opened position by the flow of air produced by the fan.
Desirably, the gas discharging structure further comprises a floor plate provided for carrying an entrance of the air introducing pipe and an exit of the gas discharging pipe thereon. The floor plate may have right and left side frames mounted thereon. One of the entrance and the exit may be positioned outwardly of the left side frame while the other of the entrance and the exit may be positioned outwardly of the right side frame.
The entrance of the air introducing pipe and the exit of the gas discharging pipe are provided at the floor plate. These pipes are difficult to view from outside the vehicle.
One of the air introducing pipe and the gas discharging pipe is provided externally of the left side frame while the other is provided externally of the right side frame. This arrangement has the advantage that the mixture discharged out of exit of the gas discharging pipe is not drawn into the entrance of the air introducing pipe.